کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4340753 | 1295809 | 2008 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Blockade of mu-opioid receptors in the medial thalamus inhibits acquisition, but not expression, of morphine-induced conditioned place preference Blockade of mu-opioid receptors in the medial thalamus inhibits acquisition, but not expression, of morphine-induced conditioned place preference](/preview/png/4340753.png)
The medial thalamus contains abundant mu-opioid receptors and is activated by acute morphine administration. However, the role of the medial thalamus in the rewarding effects of morphine is unclear. The present study examined whether mu-opioid receptors of the medial thalamus influenced the acquisition and expression of morphine-induced conditioned place preference (CPP) in rats. An unbiased apparatus and biased subject assignment were used. Administration of morphine in increasing doses (2 mg/kg, 4 mg/kg, 6 mg/kg, 10 mg/kg, s.c.) was paired with an initially non-preferred chamber and saline administration was paired with an initially preferred chamber. Conditioning trials were conducted twice daily for 4 days. Microinjection of the irreversible mu-opioid receptor antagonist, β-funaltrexamine (5 μg/rat), into the medial thalamus 23 h prior to each morphine conditioning completely blocked the acquisition of CPP. However, microinjection of β-funaltrexamine into the medial thalamus after morphine conditioning trials, but 23 h prior to a test session, had no effect on the expression of CPP. It is concluded that mu-opioid receptors in the rat medial thalamus are involved in the acquisition, but not expression, of morphine-induced CPP.
Journal: Neuroscience - Volume 151, Issue 4, 19 February 2008, Pages 948–954